RESISTANT HYPERTENSION AND ASSOCIATED FACTORS OF REFRACTORY BLOOD PRESSURE CONTROL AMONG THAI HYPERTENSIVE PATIENTS

Objective: Resistant hypertension (RH) is associated with increased cardiovascular morbidity and mortality. There is limited data of prevalence and associated factors of RH in Thai hypertensive patients. Design and method: We conducted a retrospective chart review from Electronic Medical Record of all hypertensive out-patients attending our tertiary health care center (HRH Princess Maha Chakri Sirindhorn Medical Center) during January 2021 until December 2023. We included the participants with RH if their systolic blood pressure (SBP) or diastolic blood pressure remained >/= 140 mmHg or > /=90 mmHg, respectively, despite the use of optimal or maximally tolerated doses of a three-drug combination, including a diuretic, and an appropriate lifestyle modification. They were classified as a group of uncontrolled or controlled BP, according to their office BP. The patients with secondary hypertension (HT) were excluded. Collected data consisted of sociodemographic and lifestyle factors, measurements for body mass index and BP along with self-reported adherence to treatment, underlying disease, laboratory findings, anti-hypertensive medication, microalbuminuria, ankle-brachial index(ABI), and electrocardiographic data. Logistic regression models were used to evaluate the associated factors of refractory BP control. Results were reported as odds ratios(OR) with 95% confidence intervals(CIs). Results: Totally 172 RH out-patients (female, 55.8%) were included with a mean age of 65.8±11.9 years, body mass index of 27.3±5.6 Kg/m2 and mean duration of HT=8.5±3.5 years. 45.3% classified as uncontrolled HT group, while 54.7% had well controlled BP. The prevalence of RH was 12.6%. Average number of anti-HT prescriptions was 3.3±2.6 (uncontrolled: 3.4±0.6 vs. controlled: 3.3±0.55, P=0.2)with range 3-5. The significant predictors of uncontrolled hypertension in RH are baseline SBP (adjusted OR =1.025; 95%CI: 1.003-1.047) and prescription of angiotensin-converting enzyme inhibitors (ACEIs)(adjusted OR = 3.200; 95%CI: 1.157-8.852). Overall, hypertension-mediated organ damages (HMOD): microalbuminuria, left ventricular hypertrophy, and ABI were investigated less than 36.6%. Conclusions: Our findings demonstrated the similar prevalence of RH with other studies. Prescription anti-HT medication, especially ACEIs in patients with RH should be more careful. Following the guideline to investigate HMOD is quite a bit that indicates to explore the causes, and encourage the physicians more compliance with current practice guidelines.